Gear lapping and finishing machine



June 17,1941. .J, DRADER ETAL 2,245,554

GEAR LA-PPING AND FINISHING MACHINE Filed Aug. 24, 1955 4 sheets-sheet 1 V June 11,1941. 1c. RAIDER mL' v Y 2,245,654

GEAR LAPPING AND FINISHING MACHINE FiledlAug. 24, 1955 4 Sheets-Shed?. 2

INVENToRs.

ATTORNEYS..

June 17, 1941. J.' c. DRADER ET'AL v2,245,654

GEAR LAPPING AND FINIS-HING MACHINE l Filed Aug. 24, 195s 4 sheets-sheet s ATTfmA/Eys.`

Patented June 17, 1941 GEAR LAPPING AND FINISHING MACHINE Joseph C. Drader and John D. Rovick, Detroit, Mich., assignors to Michigan Tool Company, a

lcorporation of Delaware Application August 24, 1935, Serial No. 37,671

6 Claims. (Cl. 51-5-26) Our invention relates to gear ilnishlng machines of the lapping, shaving and burnishing typef While various methods and machines have been l employed for lapping, bumishing and shaving gears, the present machine is a material advancement in the art of iinishing gears in view oi its accuracy `andl simplicity. The accuracy in finishing gears is produced by having the tool and gear moved during their relative operation from a pition away from a correct center distance relation to such position or slightly beyond. Such movement functions as a feed of the gear into the tool, or vice versa. One or a plurality of tools may be employedand the gear is preferably moved past the one or between the two tools from a position away from to a position on or slightly beyond the shortest radial relation therebetween. Such radial relation disposes the gear and tool or tool in correct center distance relation to each other. When cluster or herringbone gears are employed, two or more cutting tools may be utilized by preferably employing a. tool on each gear portion of the cluster or herringbone gear. The machine may be made automatic to advance the gears between the two cutting tools, in which instance the gear would be fed 'at a rapid speed into mesh with the two gears, after which it will be slowly fed therebetween to a position on or slightly beyond the center line between the two tools. Thereafter the carriage would againA .tool which may be fed relative to the gear to have the gear machined to 'a propel:l diameter when the tool is fed to or beyonda plane through the .center line of the gear normal to the tool feed movement; to provide a machine with two tools which are spaced apart such a distance that gear passing therebetween will be finished to accurate dimensions; to provide a machine in which one of the tools is driven for driving the gear and the second tool, the latter of which may have a brake applied thereto, to construct lthe machine to have the tools mounted to be tilted to a position at an angle to the plane of the gear; to provide a plurality of tools in different planes either laterally, angularlyor both to operate on diiierent gears of a group; to provide a machine which automatically feeds the gears between the two tools to have a continuously operating machine; and in general, to provide a machine for iinishing gears which is simple in construction, ac-

curate in machining and economical of manufacture.

Other objects and features oi novelty of our invention will be either specifically pointed out or will become apparent when referring, for a better understanding of our invention,- to the following description taken in conjunction with the accompanying drawings wherein: l

Figure 1 is a view. partly in section and partly in elevation, of a machine embodying features of our invention;

Fig. 2 is a pian view of structure illustrated in Fig. 1;

Fig. 3 is a view of structure, similar to that illustrated inv Fig. 2, showing a modified arrangement of the tools and gears;

Fig. 4 is a View of structure, similar to that illustrated in Fig. 1, showing a modified iorm thereof;

Fig. 5 is a view of structure, similar to that illustrated .in Fig. 4, showing a further modified form of our invention;

Fig. 6 is a broken view, in elevation, of a ma.- chine for continuously machining gears which are fed therethrough;

Fig. 7 is a sectional view of the structure illustrated in Fig. 6, taken on the line 12-1 thereof Fig. 8 is an enlarged sectional view of the structure illustrated in Fig. '1, taken on the line 8-8 thereof.

Fig. 9 is a plan view of a right and left hand spiral tool operating on a spur gear;

Fig. 10 is a view in elevation of a pair oftools disposed in relation somewhat similar to that illustrated in the machine in Fig. 1, showing the gear moved on an arc between the tools;

Fig. 11 is a view of structure, similar to that illustrated in Fig..5 with the gear moved on an arc, inwardlyv presented relative to the tool;

Fig. 12 is a view of structure similar to that illustrated in Fig. 11, with the gear moved on an arc, outwardly presented relative to the tool; and

Fig. 13 is a view of structure in which the principles utilized in the structure of the above iigures are employed for iinishing internal gears.

` Fig. 1, we have illustrated a finishing .machine comprising a base II supporting a motor I2 for driving a fluid pump I3 which operates the ma.- chine. 'Ihe base supports ways I4 in which carriages I5 are shiftable by means of lead screws I5 and clamped into position by suitable bolts I'l. The carriage I5 on the right hand side of the iigure is provided with aV iiuid motor I8 which drives a shaft .I9 in rotation. 'I'he shaft drives through gears 2|, a shaft 22 and a worm 23 which rotates the worm wheel 24. 'I'he worm wheel 24 is mounted on a shaft 25 on which the tool 26 on the right hand side of Fig. 1 is mounted. The motor I8 is rotatable within a head 21 on the carriage i8 to permit the tool 28 tobe disposed at various angles relative to the gear 28 to be machined, as illustrated in Fig. 2. The carriage w I l on the lett hand side of the gure may be constructed in the same manner :is that on the right hand side, and carries a head 8i provided with a. suitable internal uid brake (not shown),

- for applying a load on the tool 28 mounted thereon. In the present instance, the v'tool 28 at the left of Fig. 1 is illustrated as being mounted journaled in the shaft 28 on a head 8|, which is secured by a bolt 82 to the upstanding portion of the carriage i5 for adjustment about the axis of the bolt to permit the tool to be shifted to a predetermined angle relative to the gear 28 as illustrated in Fig. 2. In this construction the teeth of the tool 28 are of mating width so that both sides of the teeth are machined during the advancement of the gear 28 therebetween. When a burnishing or lapping operation is to be performed, the teeth of the tool may be thinner than required for mating relation with the teeth of the gear and for this reason a brakeis employed to have the driving side of the driving tool 28 operate on one side oi' the teeth of the gear while the teeth on the opposite loaded tool 28 operate on the opposite sides of the teeth of the gear.

The base ii also supports a column 88 centrally ai' the machine between the two tables I8. A carriage 88 is slidable on the column through the adjustment of a lead screw 85 and is provided with a horizontally extending portion 88 on which I :through the adjustment of the lead screw 85 the tool 28 is fed from a position above or below the y center line'between the tools to a position on or below or above, 'respectively` the center line between the tools.

Through the angular disposition of the tools relative to the gears a lateral component of movementis provided between the'teeth of the gear and tool which, during the machining operation, tendsto compensate for the deforming of the gear teeth due to roll. Such deforming on the roll is entirely eliminated when employing a tool having teeth provided with cutting edges similar to those described and claimed in the co-pending application of W. F. Dalaen, Serial No. 554,193, led July 13, 1931, and assigned to the assignee present invention.

Machining is produced by the lateral component of movement to cut uniformly at the crown, Athrough the pitch line andthe root of the'teeth, thereby accurately forming the teeth to true involute shape. While some-methods employed in the art rely upon an additional lateral feed movement between the tool or tools and the gear, in the present instance such feed may be elim.-

inated -since the particular relative movement from oi! to on center position of the gear. and

tool issumcient to produce accurate machining` component of slippage to thereby lap or burnish substantially a When shaving is employed, the cutting edges are so disposed as to cut only due to the lateral component of movement between the angularly disposed teeth ofthe tool and the straight teeth of the gear which thereby cut uniformly from the crown, through the root and pitch line of the gear cutting tool may have the teeth disposed at anA angle of thirty degrees while the other tool may have the teeth disposed at a sixty degree angle, the angular diil'erence in the planes ofoperation of the gear and tools being fifteen degrees (15). This angular difference may vary and can be obtained by changing the angular relation oi' the teeth.

l In Fig. 3, we have illustrated the gear as being of the herringbone type, having two gear segments-with the `helix angle oi.' the teeth disposed -in the opposite hands. One cutting tool operatesy on one oi' the segments, while the other tool opcrateson the other segment of the gear. The machine is otherwise operated in accordance with the above described manner.l To eect the 'adjustment of the tools laterally, ways 88 are provided on the carriage i5 which permits the heads 21 and 8| to be adjusted laterally of the plane through the gear to operate on different segments of the herringbone gear, as illustrated. It

is to be understood that it is within the purview ment obtains as on a herringbone gear.

of my invention to employ the two tools on each of the separate segments of the herringbone gear following the exact teaching of the structure illustrated in Figs. 1 and 2.

0n a cluster type of gear the same arrange- Two tools may operate on a single gear of the cluster or one tool may operate on one gear of the cluster while one or more additional tools operate on -fthe one or more additional gears` of the cluster.

5'5 byA reversing the valve controlling the flow of fluid through the motor. 4

In Fig. 4, we have illustrated a modiiled form of the machine illustrated inFig. l, ,wherein the carriage Il at lthe left-hand side of the ligure, as

viewed in the drawing, has a spring 88 interconnected betweenthe carriage support il and the carriage to urge the carriage toward the gear to force the ltool into intimate engagement therewith. In this construction the exact centering of the gear 28 relative to the tool 28 is effected between the two shafts of the gear and tool, while the shaft of the tool which is spring pressed need not be accurately located since the spring will force it into intimate contact with the gear. In this manner the vsame results will obtain as when practicing the invention illustrated in Figs. l and 2 while at the same time the difficulty of acuniform shape to the teeth.

- of the trainll.

is utilized. This machine will operate in the same manner as that illustrated in Fig. 4 when the tool which is spring pressed is eliminated. In the present construction a single support I4 is utilized for the carriage I 5 and head 21, which follows the construction of the head illustrated in the foregoing figures. Oppositely disposed to the support i4 is a column 48 which projects from the base I I carrying ways 45 on which a carriage 5i is movably adjusted by a leadl screw 52. The carriage 5i supports a carriage 31 having a head and tail stock similar to thosevdescribed above relative to structure illustrated in Figs.`1 and 2. In the figure, we have illustrated the axis of the gear and tool as being on correct center distances after the tool has been fed downwardly from a position above that shown to a position of correct center distance relation, which lis. the position inwhich the gear is completely machined. During the downward feeding of the gear to At the loading position, a stop Il, which may be suitably stationarily supported upon the machine frame, is employed to engage the shaft 18 of the gear to prevent the gear from coming in-to mesh with the teeth of the tool 65 until after the gear has been advanced 'from loading position. Thereafter the spring pressed arms 15 will move the gear to be machined into mesh with the teeth of the tool tl. The gear is then running in synchronism with the tool 69 and since the tool -84 is running in synchronism with the last named tool, the gear will fall into mesh with the teeth of the gear 54 when rapidly advanced into machining position.

A sloping element 89, also suitably supported upon the machine frame, is positioned at the unloading station to engage the ends of the shaft 18 of the gear to cause it to move out of the slot 1.1 against the bias of the arms 15 tobe ejected correct center distance relation with the tool, the

machining of the teeth will take place due to the driving of the tool 28 which machines the teeth during the downward feeding movement.

Referring to Figs. 6, 'i' and 8, we have shown a further form of the invention wherein an auto' matic machine isy provided wherein the gears are continuously brought into engagement with the on the element 59 for supporting a tool 54 and a gear 65. The shaft 86 is carried in suitable bearings -61 and 68 on the base Ii for supporting a second 'tool 89 in aligned spaced relation with the tool 64. The shafts are interconnected by a train ofgears 1I for maintaining the driving of the tool in synchronized relation. The train of gears is so mounted as to permit the adjustment of the two cutting tools 64 and 59 toward and away from each other to conform to the diameters of different gears to be machined. A pair of spiders 12 are mounted on opposit sides of the tool 69, having hubs which engage the shaft 66. The spiders support projecting arms 13 which are retained together by pins 14 which also support arms 15 that are urged inwardly toward the shaft 66 by springs 16. The arms 13 are provided with slots 11 for receiving a shaft v.18 on a gear 19 to be machined. The hub of the right-hand spider 12 is provided with a gear 8| which meshes with a gear 82 mounted on a shaft 83 in extension of one of the gears The driving of the gear Il through the gear 82 and the shaft Il from a slowly operating gear of the train, provides a feed movement of the spiders whichslowly advances the gears 19 between the toothed tools. and 59. A clutch 84 is provided on one side of the gear 8i operated by a plurality oi.' cams l5 on the opposite side of the gear 8l4 which periodically engage an element 86 to. lock the gear to the shaft 66 to have the spiders and gear rotate with the tool B9. The operation of the clutch advances a gear fro'm nished position to unloading position, and advances another gear from loading position into mesh with the tools where they are advanced by the feed movement above mentioned. An overrunning clutch 81 permits the rapid advancement of the gear 8| relative to theshaft 83.

from the machine. It is only necessary for the operator to dispose a gear in the slot 11 after the arm 15 has been drawn therefrom and release the arm to permit it to engage the shaft of the gear to forcethe gear onto the stop 88 and thereafter to force the gear into mesh with the teeth of the tool 59 when the spider is advanced away from the stop position.

The driving of the tool 69 is effected in the manner abovepointed out through the operation of the motor in the head 21 and the Icontinued actuation of the machineis thereby eiected. As soon as the gear has reached a center-line position between the two tools 64 and 59, one ofthe cams will cause the'iinger 86 to throw in the clutch to advance a new gear into position to be machinedand be fed to or beyond tool center line position through the operation of the shaft 83 and gears l2 and Il. When gears lof different diameters are to be machined, the tools 64 and i9 may be adjusted closer together or farther y apart, as the case may be, the disposition of the vtrain of gears 1I being such as to permit such adjustment while maintaining the operating relation lof the gears. The elements 13 are adjustable radially of the spiders 12 through the engagement of a slot with a clamping bolt Si. A machine for lapping, bumishing or shaving gears may be constructed in this manner and continuous operation of the machine is thereby provided to; have the gears automatically advance into machining position and slowly fed through the tools without stopping or adjusting the machine.

The machine just described has the gear and tools disposed in the same plane with the parallel axes. The machine illustrated in Figs. 1 and 2 could have gear supports mounted on an endless belt to advance the lgears between the tools 2| 'in the same manner. 'This would provide an.

' automatic machine in which the tools are tiltable relative to each other and the gear. It is also to be understood that the table for supporting the gear can be machine-fed through the tools rather than hand-fed, as illustrated in Figs. l to 5.

In Fig. 9, we have illustrated a pair of tools.

9i and operating on a'roughed out gear 93.

V.The gear may bey mounted in the machine as illustrated in the various figures and operated in the manner set forth hereinabove. It will be noted, however, that-the gears 9| and 92 are in lthe same plane, or substantially so, caused by the y trated in the iigures of the drawings, disposed relative'to each other in accordance with the diameter of the gear to be machined and tilted at desirable angles relative thereto. The support for the gear differs from the support Iorvthe gear illustrated in Fig. 1, in that the gear is moved in an arcuate path following the arcl the same as that of the gear in the machine illustrated in Fig. 6.

A single tool 94 is employed in the structure illustrated in Fig. l1, the gear following a curved path which is inwardly presenting relative to the tool 94. A tool 95 is employed in the structure illustrated in Fig. 12, the gear 86 following the curved path 91 which is outwardly presenting relative to the tool 95. Further advantages are provided when operating a gear and tool when disposed as in the structure illustrated.

In Fig. 13, we have illustrated the above principles of meshing gears applied to the finishing of internal gears. In the structure illustrated. an internal gear 98 is operated on by a tool 8l. The tool is mounted eccentric to move on an arc l to have the teeth of the tool advance in depth into the teeth of the gear during the time one is driven relative to the other. In any instance, the lateral or arcuate movement of the gear or tool relative to each other is that tol produce a movement between the teeth of the gear and tool from slight contact to fullcontact during the relative driving thereof. The gear is preferably mounted to tilt so as to be disposed at an langle to the tool. Such movement of the gearand tool relative to each other should occur at least untilthe teeth exactly mate, that is to say, until the axes of the gear and tool are on exact center distance. Preferably the gear and tool are moved beyond this position as is necessary in some of the structures illustrated. It is to be also understood that the operation of the gear and tool when only a single tool is employed is such that the direction oi rotation is reversed so that machining will occur on both sides of the teeth of the gear. In this construction, the gear is preferably moved from a position of slight contact through a position on correct center distance, and finally to a position of .slight contact beyond ,fthe center pomtion,

whereupon the direction of rotation is changed and the feed operation repeated so as to thereby machine both sides of the teeth.

While we have described and illustrated several embodiments of .our invention, it will be apparent to those skilled in the art that various changes, omissions, additions and substitutions may be made therein without departing from the spirit and scope of our invention, as set forth in the accompanying claims.

We claim as our invention:

l. A machine for finishing gears to accurat dimension including, in combination, a rotatable gear-like tool, means for driving said tool in rotation, means for` advancing a gear to be maallel to a tangent to the tool adjacent the point of machining contact from s position "away from to a position at least o a line normal to said tangent which passes through the axis of the tool, and s second tool likewise positioned.

to have the gear pass through the center line through the tools normal to said tangent.

normal to said tangent. and means for applying abrakingloadtothelastsaidtool.

3. A machine for finishing gears to accurate dimension including, in combination, a rotatable gear-like tool, means for driving said tool in rotation, means !or advancing a gear to be machined by said` tool along a line' substantially parallel to a tangent to the tool adjacent the point of machining contact from a position away from" to a position beyond s line normal to said tangent which passes through the axis of the to'ol, a second tool likewise positioned to have the gear pass to the center line through the tool normal to said tangent. means for applying a braking load to the last said tool. and means for shifting said tool laterally of a plane through the gear.

- 4. A machine for successivelyiinishing s plurality o! gears comprising in combination a rotatable gear-like tool, means for driving said tool in rotation, a rotatable fixture adapted to support a plurality of gears in spaced relation around the periphery thereof. means for supporting said nxture so that the rotation thereof causes said gears to be successively moved into and beyond a position of machining contact with' said tool, and periodically Operable means actuated by said driving means for rotating said ilxture.

5. The method ofpilnishing gears which comprises meshing. s gear member to be finished with a gear-shaped ilnishing member having teeth conjugate to the teeth of the gear member. with the axes of said members crossed at an angle less than 30, rotating one of said members thereby driving the other member and translating one of said members relative to the other in a plane which contains the axis of said member and a gear-shaped ilnishing member having teeth Y conjugate to the teeth of the gear member, with the axes of said members crossed at an angle less than 30, rotating one of said members thereby driving the other member and translating one of said members relative vto the other in s planewhich contains the axis of said member and which plane is parallel to the axis oi said other member and in a direction making an angle of at least with the axis of said gear.

JOHN D. ROVICK. JOSEPH C. DRADER..` 

